In a so-called cloud computing environment, a virtualized application execution environment is provided for users. As the virtualized application execution environment, there is a hypervisor-based virtualization environment, for example. In hypervisor-based virtualization, a VM guest environment that is an execution environment for a virtual machine (“VM”) is provided for a user. The VM is obtained by virtualizing hardware of a host computer (also referred to as “server” in some cases) serving as a host for the VM. An operating system (OS) is activated on the VM, while an application program is executed on the OS executed on the VM.
In the hypervisor-based virtualization environment, if a task of maintaining the host computer is performed or a failure of the host computer occurs, a business process may be continued by executing live migration to dynamically migrate the VM from the host computer to be maintained to another host computer without the stop of the VM. Hereinafter, the migration of a VM or the migration of a process or the like of an application program executed on a VM is referred to as “migration”.
There are the following conventional techniques related to the virtualization of a server. A technique for estimating relative maximum load amounts of virtual machines from correlation relationships between loads of the virtual machines and executing the virtual machines on virtual machine servers (physical machines) based on the estimated maximum load amounts of the virtual machines is known (refer to, for example, Japanese Laid-open Patent Publication No. 2010-244181). In addition, a technique for causing a processor executing a virtual machine to calculate consumption power based on the amount of a resource to be consumed upon the execution of a software process and migrating the software process between the processor and another processor based on the result of the calculation is known (refer to, for example, Japanese Laid-open Patent Publication No. 2010-205200). Furthermore, a technique for estimating, for migration of a virtual computer, a load of a destination physical computer in order to inhibit a load of the destination physical computer from becoming excessive and for migrating the virtual computer if the load of the destination physical computer is in an acceptable range is known (refer to, for example, International Publication Pamphlet No. WO 2012/120664).